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Thread: I think it will work
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05-31-2011, 09:06 AM #1
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I think it will work
I have a .75hp OD condensing unit, nicely built, headmaster, LPCO, HPCO, etc.
I need a .25hp setup, any reason why I couldn't just change the compressor?
Will the over sized condensor & receiver create a restriction due to volume?
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05-31-2011, 09:30 AM #2
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Need more information...
How long is the run...
Refrigerant...
Size of the equipment...
Reason I ask is that what you have may be too much for the .25 and you may need a .50 in which you would get away with...
Hope this Helps...Isn't sanity just a one-trick pony anyway? I mean, all you get is that one trick, rational thinking, but when you're good and crazy, well, the sky's the limit!
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05-31-2011, 12:17 PM #3
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I've done similar to this numerous times with very good results. The main difference is the discharge pressure will be lower because of the oversized, 3/4 HP condenser and therefore the compressor will have a little more capacity than it would with a 1/3 HP condenser.
Typical refrigeration condensing units run at about a 30+ºF TD (T condensing - T ambient), so I would expect this unit to run at around a 10ºF TD. At a 90ºF ambient, the SCT would be approximately 100ºF. Take this into account when selecting a compressor to match your design load.
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05-31-2011, 05:43 PM #4
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Im curious if you do something like this will the oversized condenser need more refrigerant backed up by the headmaster in the cold winter months to mantain a minimum head pressure?
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05-31-2011, 05:47 PM #5
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Yes, because the extra refrigerant charge is determined by the volume of the condenser, along with the lowest ambient temp for your area.
Originally Posted by dangpgt97
Experience is what you have an hour after you need it.
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05-31-2011, 07:09 PM #6
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Originally Posted by dangpgt97
That's a very good question. Originally Posted by baub
In this case, the condenser would be about three times the size that of a "normal" system, so the total volume would be greater in about the same proportion. It would follow that the volume required to flood the condenser at lower ambients would then be greater.
If you want to try your hand at the hand calcs of such a questions, here's the Sporlan methodology:
http://www.sporlanonline.com/90-30-1.pdf
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